Ebola and evidence: Five years on

On March 23rd 2014, the Ministry of Health in Guinea notified the World Health Organization (WHO) of an Ebola outbreak in the South-eastern region of the country. What was to follow was the deadliest Ebola outbreak ever recorded, resulting in an epidemic primarily affecting Guinea and its neighbours Sierra Leone and Liberia. Over the next two years 28,616 cases and 11,323 deaths were reported, although this is likely to be an underestimate due to the significant number of unreported cases and deaths. 1(p32).

Questions loomed about how the 2014-2016 outbreak spiralled so out of control with such devastating consequences. The combination of social, cultural and economic factors played a huge role in perpetuating the outbreak, but one driver was clear – the initial weak response from the international community and specifically the WHO.

It was not until August 4th, after more than 1000 deaths, that the WHO declared the outbreak a ‘Public Health Emergency of International Concern’(PHEIC). The WHO has been strongly criticized by many different actors, both for its failure to act quickly enough and because it had supposedly ‘actively downplayed’ the crisis, particularly in the latter’s early phases. Declaration of a PHEIC opened the door to more funding, expertise and international cooperation to help halt the spread of disease.

Once mobilised, the international response was huge, supporting national agencies and ministries of health in the affected countries. Traditional interventions to break transmission chains such as active-case finding, contact tracing, and isolation were employed at the start of the outbreak. However, as the number of cases and contacts grew, with over 500 new cases a week it soon became an impossible task. Broader public health measures such as social mobilisation and community engagement played a large role in driving down the epidemic. Community leaders, pastors and chiefs were central to changing high-risk behaviours and promoting safe burial through radio shows, community meetings and trainings.

As with any outbreak, surveillance systems are crucial to understand transmission chains and to guide evidence-based decision making. Many researchers embraced WHO’s calls for a culture of openness, sharing data on genomic sequencing on open-access sites. Although the accuracy of data collection improved as the outbreak progressed, the lack of accurate epidemiological data and weak data management systems delayed implementation of appropriate evidence-based interventions.

Prior to the outbreak Sierra Leone had some of the highest rates of maternal and child mortality globally. During the outbreak studies suggest that non-Ebola mortality and morbidity increased. Healthcare workers were disproportionately infected with Ebola, and by May 2015, 6.87% of Sierra Leone’s brave doctors, nurses and midwives had died of Ebola. This has had a lasting effect on health outcomes, with one study identifying 2,819 extra deaths in Sierra Leone from tuberculosis, AIDs and malaria during the crises 2. It was imperative that health facilities remained opened. Ebola holding units were set up in existing government hospitals. These were retrospectively identified as safe and effective, and importantly did not divert resources from non-Ebola health services 3.

The scientific community came together to conduct accelerated vaccine trials and drug trials, such as the use of zMAPP experimental serum, in an attempt to find both a prevention and a cure. On 29th March 2016, the WHO lifted its classification of the outbreak as a PHEIC.

Two years later on the 1st August 2018 the Ministry of Health of the Democratic Republic of Congo (DRC) declared a new outbreak of Ebola in the Northern Kivu province of the country. As of the 20th February 2019 there have been 853 cases and 531 deaths4. The WHO has described the combination of a protracted conflict and socio-economic factors as ‘the perfect storm’ that could lead to the outbreak escalating and crossing borders. Recently there have been calls by some academics calling for the WHO to declare the current outbreak in DRC a PHEIC.5

The 2013-2016 outbreak required a steep learning curve for the international community and some lessons learned are being implemented today in Northern Kivu. For example, the rVSV-ZEBOV vaccine, trialed in Guinea in 2015, is currently unlicensed but is being used on a compassionate basis in Northern Kivu, with only those at high risk being vaccinated.

Despite successes such as the vaccine, many interventions employed during the West African outbreak have a limited evidence base. Multiple interventions were introduced simultaneously making it difficult to disentangle the individual effects of each intervention. Ideally interventions should be evaluated using the gold standard of randomized control trials, but this is and was ethically and practically challenging to conduct in an outbreak setting. Instead, interventions were often evaluated using anecdotal evidence and in many cases causality was assumed if the introduction of an intervention was subsequently followed by a decline in cases. Retrospectively, the interventions employed are difficult to evaluate as there was little documentation monitoring interventions. This lack of rigorous scientific investigation makes it difficult for public health professionals to distinguish ‘good’ interventions from ‘bad’ ones further compounding the ability to respond appropriately to an Ebola outbreak.

Despite these difficulties, communities and individuals affected by Ebola are entitled to, and deserve, interventions that are firmly based in evidence. The 2014-2016 outbreak highlighted the need for there to be less of a disconnect between academia and the public health operational world. Here at Evidence Aid, the Ebola Collection team have worked to collate available evidence in the form of systematic reviews to help guide and encourage decision-makers to implement evidence-based interventions.

Gostin L, Phelan A, Coutinho AG, et al. Ebola in the Democratic Republic of the Congo: time to sound a global alert? The Lancet. 2019;393(10172):617-620. doi:10.1016/S0140-6736(19)30243-0

About the author:

Hannah is currently studying Medicine at King’s College, London. She holds an honorary research position at Public Health England conducting research in refugee and migrant health and prior to starting medical school worked in Sierra Leone on the EBOVAC vaccine trial led by the London School of Hygiene and Tropical Medicine.

Evidence Aid passionately believes in making evidence freely available to humanitarians, whoever and wherever they are. But our resources need money to produce, translate and maintain.

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